Automotive Technology/Suspension and Steering
This page is written for those taking the ASE A4 test
- Always mark the placement of any part before removal
Steering edit
Always disable the Air Bag system before any change to the steering column.
Steering Columns should be locked into place to preserve timing and prevent overextending the clock-spring.
Replace Bushings when they no longer hold the part in position. Replace Bearings when they have any visible play, or have a turning torque outside of specification.
Adjustments can affect front wheel toe
Diagnosis edit
Bump steer can be caused by
- Loose idler arm
- Loose rack mountings
- Loose or damaged mounting
Steering wheel free play can be caused by
- Worn couplings
- worn u joint
- Loose mounting
Steering problems are sometimes subframe alignment problems
Manual Steering Gears edit
Also known as worm gears
Noises, binding, looseness, hard steering point to bearing and lubrication problems.
Rack and Pinion Steering Gear edit
Other parts edit
Air bag Steering wheel Clock spring
Worm gear Idler arm Rack and pinion
Tie rods
Power Steering Units edit
Power steering uses hydraulic pressure to apply force to the worm gear or rack
Diagnosis edit
Weeping, or a slight fluid leak requires repair or replacement
- inspect power steering fluid
- Remove and replace power steering pump belt, tensioner, pulley
- diagnose power steering pump problems
- Remove and replace power steering pump
- power steering pressure test
- Remove and replace power steering hydraulics
- Steering gear worm bearing preload and sector lash
- Remove and replace steering gear seals and gaskets
- Remove and replace rack and pinion unit
- Remove and replace rack and pinion steering gear bellows/boots.
- flush, fill, bleed power steering hydraulics
- Diagnose, Remove and replace variable-assist steering systems
- Rack and Pinion Steering
- can provide assistance by applying pressure to one side
Steering Linkage edit
- Inspect and adjust steering linkage geometry
Pitman arm edit
Pitman arm is only bent in collisions, and wears on other parts. These are pressed on, and are difficult to separate from the splines.
Center link edit
If bent, will affect front wheel toe
Idler arm edit
- Remove and Replace tie rods
- Remove and Replace steering linkage damper
Remove and Replace
Suspension edit
Front Suspension edit
Rear Suspension edit
Alignment edit
Frame edit
Springs edit
You should understand spring frequency, even if you never measure the frequency of the spring. Most spring are made of a chrome-vanadium alloy. Very tough stuff.
- Constant-velocity joint
- Usable in torque transfer
Suspension edit
ASE Task List edit
Glossary edit
- Aspect ratio
- Bead
- The lip of the tire that seals the rim flange
- Belt
- Material under the tread
- Center section AKA Spider
- Center of a steel wheel
- Conicity
- DOT tire code
- E-metric tire
- High flotation tire
- Inner liner
- Load index
- Lug nuts
- Major splice
- Offset
- Ply steer
- Rim width
- Run-flat
- Sidewall
- Speed rating
- TPC
- Unsprung Weight
- Weight below the spring in a vehicle
- Uniform Tire Quality Grading System (UTQG)
- Tires sold in the USA are rated in Tread wear, Traction, and Temperature Resistance as per NHTSA.
- Wear bars
- raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit